Electrosurgical cutting and sealing instruments with jaws having a parallel closure motion

ABSTRACT

A surgical instrument comprising, a shaft, and an end effector comprising first and second jaw members and a reciprocating member. The end effector may additionally comprise a first push rod member having a distally directed end pivotably coupled to the first jaw member and a proximally directed end pivotably coupled to the shaft at a first pivot point as well as a first linkage member having a distally directed end pivotably coupled to the first jaw member and a proximally directed end pivotably coupled to a second pivot point. In this way, distal motion of the reciprocating member may exert a force on the first and second jaw members causing the first and second jaw members to translate towards one another in a substantially parallel motion.

BACKGROUND

Various embodiments are directed to electrosurgical cutting and sealinginstruments with jaws having a parallel closure motion that may be used,for example, in open and minimally invasive surgical environments.

Minimally invasive procedures are desirable because such procedures canreduce pain and provide relatively quick recovery times as compared toconventional open medical procedures. Many minimally invasive proceduresare performed with an endoscope (including without limitationlaparoscopes). Such procedures permit a physician to position,manipulate, and view medical instruments and accessories inside thepatient through a small access opening in the patient's body.Laparoscopy is a term used to describe such an “endosurgical” approachusing an endoscope (often a rigid laparoscope). In this type ofprocedure, accessory devices (such as end effectors for creatingenergy-induced tissue welds) are inserted into a patient through trocarsplaced through the body wall. Still less invasive treatments includethose that are performed through insertion of an endoscope through anatural body orifice to a treatment region. Examples of this approachinclude, but are not limited to, cystoscopy, hysteroscopy,esophagogastroduodenoscopy, and colonoscopy.

Many of these procedures employ a flexible endoscope during theprocedure. Flexible endoscopes often have a flexible, steerablearticulating section near the distal end that can be controlled by theclinician by utilizing controls at the proximal end. Some flexibleendoscopes are relatively small (1 mm to 3 mm in diameter), and may haveno integral accessory channel (also called biopsy channels or workingchannels). Other flexible endoscopes, including gastroscopes andcolonoscopes, have integral working channels having a diameter of about2.0 to 3.7 mm for the purpose of introducing and removing medicaldevices and other accessory devices to perform diagnosis or therapywithin the patient. For example, some end effectors are used to createan energy-induced weld or seal. Certain specialized endoscopes orsteerable overtubes are available, such as large working channelendoscopes having a working channel of 5 mm, or larger, in diameter,which can be used to pass relatively large accessories, or to providecapability to suction large blood clots. Other specialized endoscopesinclude those having two or more working channels.

A common task both in minimally invasive and open surgical environmentsis to grasp, cut and fasten tissue while leaving the cut ends hemostatic(e.g., not bleeding). For example, it is often desirable to cut and sealbodily lumens, such as individual blood vessels or tissue includingvarious vasculature. When sealing a fluid-carrying bodily lumen, it isoften necessary for the seal to have sufficient strength to preventleakage of the fluid, which may exert considerable fluid pressure.

Instruments exist for simultaneously making a longitudinal incision intissue and fastening the tissue on opposing sides of the incision. Suchinstruments commonly include an end effector having a pair ofcooperating jaw members that, if the instrument is intended forminimally invasive applications, are capable of passing through acannula passageway or endoscopic working channel. In use, the clinicianis able to close the jaw members to clamp the tissue to be cut. Areciprocating cutting instrument (or knife) is drawn distally along thejaw members to transect the clamped tissue. Simultaneously, a fasteningmechanism fastens the cut ends of the tissue on opposing sides of theincision. Known fastening mechanisms include staples, sutures or variousinstruments utilizing energy sources. For example, various energysources such as radio frequency (RF) sources, ultrasound sources andlasers have been developed to coagulate, seal or join together tissuevolumes.

SUMMARY

Various embodiments are directed to a surgical instrument comprising ahandle a shaft, an end effector and a reciprocating member. The shaftmay be coupled to the handle and may extend distally along alongitudinal axis. The end effector may be positioned at a distal end ofthe shaft and may comprise first and second jaw members, first andsecond push rod members, as well as first and second linkage members.The first and second jaw members may, respectively, define first andsecond longitudinal slots. The first push rod member may have a distallydirected end pivotably coupled to the first jaw member and a proximallydirected end pivotably coupled to the shaft at a first pivot point. Thesecond push rod member may have a distally directed end pivotablycoupled to the second jaw member and a proximally directed end pivotablycoupled to the shaft at the first pivot point. The first linkage membermay have a distally directed end pivotably coupled to the first jawmember and a proximally directed end pivotably coupled to a second pivotpoint. The second linkage member may have a distally directed endpivotably coupled to the second jaw member and a proximally directed endpivotably coupled to the second pivot point. The reciprocating membermay be translatable distally and proximally parallel to the longitudinalaxis through the first longitudinal slot and the second longitudinalslot. A distal portion of the reciprocating member may define a blade.Distal motion of the reciprocating member may exert a force on the firstand second jaw members causing the first and second jaw members totranslate towards one another in a substantially parallel motion.

Various embodiments may be directed to a surgical instrument comprisinga handle, a shaft, an end effector and a reciprocating member. The shaftmay be coupled to the handle and extending distally along a longitudinalaxis. The end effector may be positioned at a distal end of the shaft,and may comprise first and second jaw members, a first push rod memberand a first linkage member. The first and second jaw members may,respectively, define first and second longitudinal slots. The second jawmember may be coupled to the shaft. The first push rod member may have adistally directed end pivotably coupled to the first jaw member and aproximally directed end pivotably coupled to at least one of the shaftand the second jaw at a first pivot point. The first linkage member mayhave a distally directed end pivotably coupled to the first jaw memberand a proximally directed end pivotably coupled to at least one of theshaft and the second jaw at a second pivot point. The reciprocatingmember may be translatable distally and proximally parallel to thelongitudinal axis through the first longitudinal slot and the secondlongitudinal slot. The distal portion of the reciprocating member maydefine a blade. Distal motion of the reciprocating member may exert aforce on the first and second jaw members causing the first jaw memberto translate towards the second jaw member in a substantially parallelmotion.

FIGURES

Various features of the embodiments described herein are set forth withparticularity in the appended claims. The various embodiments, however,both as to organization and methods of operation may be understood inaccordance with the following description taken in conjunction with theaccompanying drawings as follows.

FIG. 1 illustrates one embodiment of a transection and sealinginstrument, which may be used, for example, with an endoscope.

FIG. 2 illustrates one embodiment of the transection and sealinginstrument of FIG. 1 for use in electrosurgical applications.

FIGS. 3 and 4 illustrate one embodiment of an end effector of a surgicalgrasping instrument adapted for transecting captured tissue andcontemporaneous sealing of the captured tissue with RF energy delivery.

FIGS. 5 and 6 illustrate one embodiment of the reciprocating membershown in FIGS. 3 and 4.

FIGS. 7 and 8 illustrate one embodiment of the actuation of areciprocating member shown in FIG. 3 from a first retracted position toa second extended position to move the jaws of the end effector from anopen position to a closed position.

FIG. 9 illustrates an end view of one embodiment of the reciprocatingmember of FIG. 3 with the jaws of the end effector in phantom view.

FIG. 10 illustrates a cross-sectional view of the embodiment shown inFIG. 9 along a cross-section taken at a position proximally located fromthe end view shown in FIG. 9.

FIG. 11 illustrates one embodiment of the jaw of the end effector ofFIG. 3 de-mated from the end effector.

FIGS. 12-14 illustrate one embodiment of an end effector having a singlerotating jaw member.

FIGS. 15-18 illustrate another embodiment of an end effector having asingle rotating jaw member.

FIG. 19 illustrates one embodiment of the reciprocating memberconfigured with separate elevated step or cam surfaces in the lowerflange portions that are adapted to slidably engage the ends of therectangular pins on either side of upper jaw.

FIG. 20 illustrates one embodiment of an end effector comprising a firstjaw member and a second jaw member that are configured to have aparallel closing motion.

FIG. 21 illustrates one embodiment of the end effector of FIG. 20 in aclosed position.

FIG. 22 illustrates a top view of one embodiment of the end effector ofFIG. 20.

FIG. 23 illustrates a top view of one embodiment of the end effector ofFIG. 22 according to an alternate arrangement.

FIGS. 24 and 25 illustrate one embodiment of an end effector of FIG. 20mounted to the shaft via a clevis.

FIGS. 26 and 27 illustrate one embodiment of an end effector having asingle movable jaw member.

FIG. 28 shows an example embodiment of a vessel having opposing wallportions.

FIG. 29 is a graphic illustration of one embodiment of the opposingvessel walls portions of FIG. 28 with the tissue divided into a gridwith arbitrary micron dimensions.

FIG. 30 illustrates one embodiment of the blood vessel of FIG. 28 actedupon by a device implementing a power adjustment approach to energydelivery.

FIG. 31 illustrates one embodiment of the blood vessel of FIG. 28 actedupon by a device implementing a current-path directing approach toenergy delivery.

FIG. 32 illustrates one embodiment of an endoscope (illustrated here asa gastroscope) inserted into the upper gastrointestinal tract of apatient.

FIG. 33 illustrates one embodiment of a distal portion of the endoscopeof FIG. 32, which may be used with the transection and sealinginstrument described herein.

DESCRIPTION

Various embodiments are directed to electrosurgical devices for cuttingand sealing, for example, cutting and sealing a bodily lumen. Accordingto various embodiments, the electrosurgical devices may comprise an endeffector having a pair of jaw members with a parallel closing motion.For example, substanially all of each jaw member may translate throughthe same distance to reach the closed position. Also, for example, theangular orientation of the jaw members relative to one another may bethe same when the jaw member is in the open position as when the jawmember is in the closed position. Accordingly, “milking” of tissuetowards the distal end of the end effector may be minimized. This maypromote a more even distribution of tissue between the jaw members,enhancing the efficiency of the cutting and/or sealing mechanism. Also,it may prevent situations where portions of the tissue “milk” out thedistal end of the end effector and are, therefore, not cut or sealed.

FIG. 1 illustrates one embodiment of a transection and sealinginstrument 100. The instrument 100 may be used with an endoscope,laparoscope, or any other suitable introduction device. According tovarious embodiments, the transection and sealing instrument 100 maycomprise a handle assembly 102, a shaft 104 and an end effector 106. Theshaft 104 may be rigid (e.g., for laparoscopic application and/or opensurgical application) or flexible, as shown, (e.g., for endoscopicapplication). In various embodiments, the shaft 104 may comprise one ormore articulation points (e.g., in embodiments where the shaft 104 isrigid). The end effector 106 may comprise a first jaw member 108 and asecond jaw member 110. The first jaw member 108 and second jaw member110 may be connected to a clevis 112, which, in turn, may be coupled tothe shaft 104. In various embodiments, as illustrated below, the jawmembers 108, 110 may be directly coupled to the shaft 104 and the clevis112 may be omitted. Also, for example, the jaw members 108, 110 may becoupled to the shaft via one or more push rods or other linkage devices(not shown in FIG. 1). In FIG. 1, the end effector 106 is shown with thejaw members 108, 110 in an open position. A reciprocating blade/I-beammember 340 is illustrated between the jaw members 108, 110.

According to various embodiments, one or both of the jaw members 108,110 may include, or serve as electrodes in monopolar or bi-polarelectrosurgical applications including, for example, cutting,coagulation and welding. FIG. 2 illustrates one embodiment of thetransection and sealing instrument 100 for use in electrosurgicalapplications. The jaw members 108, 110 of the end effector 106 maycomprise respective electrodes 120, 122. The electrodes 120, 122 may beconnected to an electrosurgical generator 124 via wires (not shown)extending from the end effector 106 through the shaft 104 and handle102. The generator 124 may generate any suitable type of signal forelectrosurgical applications. For example, the generator 124 may makevarious alternating current (A/C) and/or direct current (D/C) signals atsuitable voltages, currents, frequencies and wave patterns. According tovarious embodiments, the transection and sealing instrument 100 may beconfigured for monopolar operation. In this case, the end effector 106may comprise a single electrode, rather than two. According to variousembodiments, all or a portion of the end effector 106 may serve as thesingle electrode.

A translating member 116 may extend within the shaft 104 from the endeffector 106 to the handle 102. The translating member 116 may be madefrom any suitable material. For example, the translating member 116 maybe, a metal wire (e.g., a tri-layered steel cable), a plastic or metalshaft, etc. In some embodiments, one or more additional translatingmembers (not shown in FIG. 2) may be included to control the motion ofthe end effector 106 and/or the shaft 104. In various embodiments, theinstrument 100 may comprise multiple translating members 116, forexample, as described below. At the handle 102, the shaft 104 may bedirectly or indirectly coupled to an actuator 113 (FIG. 1). In use, aclinician may cause the actuator 113 to pivot along arrow 118 from afirst position to a second position. When the actuator moves from thefirst position to the second position, it may translate the translatingmember 116 distally or proximally. Distal or proximal motion of thetranslating member 116 may, in turn, cause the end effector 106 totransition from an open position to a closed position (or vice versa)and/or to perform various other surgical activities such as, forexample, severing and/or joining or welding. According to variousembodiments, the handle 102 may comprise multiple actuators 113. Whenmultiple actuators 113 are present, each actuator 113 may be used by aclinician to cause the end effector 106 to perform different surgicalactivities. In various embodiments a single actuator 113 may cause theend effector 106 to perform more than one activity. For example, aclinician may activate a single actuator 113 to force a reciprocatingmember 340 distally. This may, as described, both close the jaw members108, 110 and transect any tissue between the jaw members 108, 110.

FIGS. 3 and 4 illustrate one embodiment of an end effector 106 of theinstrument 100 adapted for transecting captured tissue andcontemporaneous sealing of the captured tissue with RF energy delivery.The end effector 106 is carried at the distal end 304 of the shaft 104that can be rigid, articulatable or deflectable in any suitablediameter. For example, the shaft 104 can have a diameter ranging fromabout 2 mm to 20 mm to cooperate with cannulae inendoscopic/laparoscopic surgeries or for use in open surgicalprocedures. The shaft 104 extends from a proximal handle, such as thehandle 102. The handle 102 can be any type of pistol-grip or other typeof handle known in the art that carries actuator levers, triggers orsliders for moving the translating member 116 or members distally andproximally to actuate the jaws as will be disclosed below. The shaft 104has a bore 308 extending therethrough for carrying actuator mechanisms(e.g., translating member 116) for actuating the jaws and for carryingelectrical leads 309 a-309 b for the electrosurgical components of theend effector 106.

FIGS. 3 and 4 show details of the end effector 106, including the(upper) jaw element 108 and (lower) jaw element 110 that are adapted toclose or approximate along an axis 315. The jaw elements 108, 110 mayboth be moveable or a single jaw may rotate to provide the open andclosed positions. In the example embodiment of FIGS. 1 and 2, both thelower and upper jaws 110, 108 are moveable relative to a rolling pivotlocation 316 defined further below.

An opening-closing mechanism of the end effector 106 operates on thebasis of cam mechanisms that provide a positive engagement of cammingsurfaces both distal and proximal to a pivoting location (i) for movingthe jaw assembly to the (second) closed position to engage tissue undervery high compressive forces, and (ii) for moving the jaws toward the(first) open position to apply substantially high opening forces for“dissecting” tissue. This feature allows the surgeon to insert the tipof the closed jaws into a dissectable tissue plane—and thereafter openthe jaws to apply such dissecting forces against the tissues.

According to various embodiments, the lower and upper jaws 110, 108 mayhave a first end 318, in the open position, that defines first(proximally-facing) arcuate outer surface portions indicated at 320 aand 320 b that are engaged by a first surface portions 322 a and 322 bof a reciprocating I-beam member 340 (FIG. 4) that is adapted to slideover the jaw elements 108, 110 to thereby move the jaws toward closedposition. FIGS. 5 and 6 show views that illustrate the cam surfaces ofreciprocating member 340 de-mated from jaws 110 and 108. The first endportion 318 of the lower and upper jaws, in the open position, furtherdefines second (distally-facing) arcuate surface portions indicated at330 a and 330 b that are engaged by second surface portions 332 a and332 b (FIG. 5) of the reciprocating member 340 for moving the jawelements to the open position. The effective point of jaw rotation maylie between the first and second arcuate cam surfaces of the jaws. Thedistal (second) end region 333 of the paired jaws is rounded with a lip334 that can serve as an electrode for surface coagulation as will bedescribed below.

In this embodiment of FIGS. 3, 4 and 5, the reciprocating member 340 maybe actuatable from the handle of the instrument by any suitablemechanism, such as actuator 113. For example, the actuator 113 may becoupled to a proximal end 341 of the member 340 and/or may be coupled toa translating member or members 116 that are, in turn, coupled to thereciprocating member. The proximal end 341 and medial portion 341′ ofmember 340 are dimensioned to reciprocate within bore 308 of the shaft104. The distal portion 342 of reciprocating member 340 carries first(lower) and second (upper) laterally-extending flanges or shoulderelements 344A and 344B that are coupled by an intermediate transverseelement 345. The transverse element 345 further is adapted to transecttissue captured between the jaws with a leading edge 346 (FIG. 5) thatcan be a blade or a cutting electrode. The transverse element 345 isadapted to slide within channels 348 a and 348 b in the paired first andsecond jaws 110, 108. As can be seen best in FIGS. 5 and 6, thelaterally-extending shoulder elements 344A and 344B define the surfaces322 a, 322 b, 332 a, 332 b that slidably engage the arcuate cam surfacesof the jaws and that apply high compressive forces to the jaws in theclosed position.

According to various embodiments, the first and second jaws 108 and 110may define tissue-engaging surfaces or planes 350 a and 350 b thatcontact and deliver energy to engaged tissues, in part, from RFelectrodes 120, 122. The engagement plane 350 a of the lower jaw 110 maybe adapted to deliver energy to tissue, and the tissue-contactingsurface 350 b of upper jaw 108 may be electrosurgically active orpassive as will be described below. Alternatively, the engagementsurfaces 350 a, 350 b of the jaws can carry any suitable electrodearrangement known in the art.

The jaws 108, 110 may have teeth or serrations 356 in any location forgripping tissue. The embodiment of FIGS. 3 and 4 depicts such serrations356 at an inner portion of the jaws along channels 348 a and 348 b thusleaving engagement planes 350 a and 350 b laterally outward of thetissue-gripping elements. The serrations 356 may be of any suitablesymmetric or asymmetric shape or combination of shapes including, forexample, triangular, rounded, sinusoidal, etc. In the embodimentsdescribed below, the engagement planes 350 a and 350 b and electrode(s)120, 122 generally are shown with a non-serrated surface for clarity ofexplanation, but such engagement planes and electrodes themselves can beany non-smooth gripping surface. The axial length of jaws 108, 110indicated at L can be any suitable length depending on the anatomicstructure targeted for transection and sealing. In various embodiments,the length L may be between 10 mm and 50 mm. In some embodiments, thelength L may be longer. For example, one embodiment of an end effector106 for resecting and sealing organs such as a lung or liver may have alength L of about 200 mm. Also, for example, for some surgical tasks,the jaws having a shorter length L may be used, including, for example,jaws having a length L of about 5.0 mm.

FIG. 9 illustrates an end view of one embodiment of the reciprocatingmember 340 with the jaws 110 and 108 in phantom view. The view shown inFIG. 9 is a head-on view with the distally positioned blade surface 346pointed out of the page. FIG. 10 illustrates a cross-sectional view ofthe embodiment shown in FIG. 9 along a cross-section taken at a positionproximally located from the end view shown in FIG. 9. The transverseelement 345 of the reciprocating member 340 may define a transversedimension d between innermost surfaces 358 a and 358 b of the flanges344A, 344B of the reciprocating member 340 and cooperating medial anddistal outer surfaces 360A and 360B of the jaws. The selected transversedimension d between the flanges or shoulders 344A and 344B thus furtherdefines the engagement gap g between the engagement planes 350 a and 350b of the jaws in the closed position. It has been found that very highcompression of tissue combined with controlled RF energy delivery isoptimal for welding the engaged tissue volume contemporaneous withtransection of the tissue. According to various embodiments, theengagement gap g between the engagement planes 350 a, 350 b may rangefrom about 0.001″ to about 0.050″. For example, the gap g between theengagement planes ranges from about 0.001″ to about 0.010″. As can beseen in FIGS. 5 and 10, the medial portion 341′ of the reciprocatingmember 340 may have an “I”-beam shape with inner surface portions 363 aand 363 b that engage the cooperating medial outer surfaces of the jaws.Thus, in various embodiments, the entire length L of the jaws can bemaintained in a fixed spaced-apart relationship to define a consistentengagement gap g. According to various embodiments, the engagement gap gmay be selected to be large enough to prevent tissue engaged between thejaws 108, 110 from being sheared and to prevent electrical shortsbetween the electrodes 120, 122.

FIGS. 7 and 8 illustrate one embodiment of the actuation of thereciprocating member 340 from a first retracted position to a secondextended position to move the jaws 110 and 108 from an open position toa closed position. Referring to FIG. 7, it can be seen that thetranslatable member 340 is being moved in the proximal direction so thatthe proximal-facing surfaces 332 a and 332 b (FIG. 5) of reciprocatingmember 340 about the outer surfaces 330 a and 330 b of the jaws thusforcing the jaws apart, for example to apply dissecting forces totissues or to open jaws 108 and 110 to engage targeted tissues forhemostasis and transection. FIG. 8 shows the reciprocating member 340after having been fully extended in the distal direction so that thedistal-facing surfaces 322 a and 322 b of reciprocating member 340 haveridden up and over the proximal arcuate surfaces 320 a and 320 b of thejaws (and medial outer surfaces 360A and 360B) thus forcing the jawstogether thereby producing a compressive force between jaws 108 and 110.According to various embodiments, the orientation of surfaces 322 a, 322b of the reciprocating member 340 and/or the arcuate surfaces 320 a, 320b may be modified to modify the compression rate provided by thereciprocating member 340. For example, the orientation of the 322 a, 322b of the reciprocating member 340 and/or the arcuate surfaces 320 a, 320b may vary from one embodiment to another, or may vary within a singleembodiment in order to cause variable compression rates within a singlestroke of the reciprocating member 340.

According to various embodiments, the jaws 108, 110 may rollably contactone another along the interface 370 between inner surfaces 372 of thefirst end 318 of the jaws. As jaws 108 and 110 articulate, the pivotpoint is moving as the point of contact changes at the interface betweensurfaces 370 and 372. Thus, the jaw assembly may not need to define atrue single pivot point as is typical of hinge-type jaws known in theart. The pivotable action of the jaws along interface 370 may bedescribed as a rolling pivot that optionally can allow for a degree ofdynamic adjustment of the engagement gap g at the proximal end of thejaws. FIG. 11 illustrates one embodiment of the jaw 108 de-mated fromthe end effector 106. Referencing FIG. 11, the jaws elements 110, 108can be retained relative to one another and the shaft 104 by means ofprotruding elements 375 that couples with arcuate slots 376 in aninternal member 377 that is fixedly carried in bore 308 of shaft 104.Alternatively, outwardly protruding elements can cooperate with slots inthe wall of shaft 104. Also, for example, the jaw assembly may(optionally) comprise springs for urging the jaws toward the openposition, or closed position depending on the desired at-rest state ofthe device.

FIGS. 12-13 illustrate an one embodiment of an end effector 1200 havinga single rotating jaw member. Like the end effector 106 described above,the end effector 1200 is carried at the distal end 304 of the shaft 104that has a bore 308 extending therethrough. According to variousembodiments, the first (lower) jaw 1210 may be a fixed extension portionof the shaft 104. As can be seen in FIGS. 12 and 13, the second (upper)jaw 1208 is adapted to close or approximate along longitudinal axis1215.

The opening-closing mechanism of end effector 1200 may provide camsurfaces for positive engagement between reciprocating member 340 andthe jaws (i) for moving the jaws to a closed position to engage tissueunder high compressive forces, and (ii) for moving the jaws toward the(first) open position thereby providing high opening forces to dissecttissue with outer surfaces of the jaw tips. The reciprocating member 340operates as described previously to reciprocate within bore 308 of theshaft 104. As can be seen in FIG. 13, the distal end portion 342 ofreciprocating member 340 carries distal first and secondlaterally-extending flange portions 344A and 344B with theblade-carrying transverse element 345 extending therebetween. Theblade-carrying member slides within channels 348 a and 348 b in thejaws.

In the example embodiment of FIGS. 12 and 13, the first and second jawmembers 1210 and 1208 again define engagement surfaces or planes 1250 aand 1250 b that deliver energy to engaged tissue. The engagement planesmay carry one or more conductor/electrodes 1255 and, in variousembodiments, may comprise a PTC matrix 1285 in at least one of the jaws'engagement surfaces 1250 a and 1250 b. In the embodiment of FIGS. 12 and13, the upper jaw 1208 has a proximate end region 1258 that, in the openposition, defines a first (proximally-facing) arcuate cam surfaceindicated at 1260 that is engaged by a first surface portion 1562 of thereciprocating member 340. The first (proximal) end region 1258 of theupper jaw, in the open position, further defines second(distally-facing) surface portions indicated at 1270 a and 1270 a′ thatare engaged by second surface 1272 of reciprocating member 340 formoving the jaw assembly to an open position.

As can be seen best in FIG. 13, the cam surfaces 1270 a and 1270 a′ maybe formed into pins or projecting elements 1274 and 1274′ that may servemultiple purposes. Referring to FIG. 14, the pins 1274 and 1274′ extendthrough the upper jaw body 1276 b and are received within arcuate bores1277 in body 1276 a of lower jaw 1210. The lower portions 1278(collectively) of the pins 1274 and 1274′ thus can retain upper jaw 1208and prevent it from moving axially or laterally relative to the jaw axis1215 while still allowing the jaw's rotation for opening and closing.The pin mechanism further allows for greatly simplified assembly of theinstrument.

The pins 1274 and 1274′ may provide additional functionality byproviding a degree of “vertical” freedom of movement within the first(proximal) end portion 1258 of the jaw. As can be seen in FIGS. 12 and19, the distal laterally-extending flange portions 344A and 344B definea transverse dimension d (cf. FIG. 19) that in turn determines thedimension of the engagement gap g of the distal end of the jaws in thejaw-closed position (FIG. 14). The transverse dimension d equals thedimension between inner surfaces of flange portions 344A and 344B thatslidably contact the outer surfaces of both jaws.

FIGS. 15-18 illustrate another embodiment of an end effector 1500 thatprovides both electrosurgical functionality and improved grasping anddissecting functionality for endoscopic surgeries. In FIGS. 15-18, boththe upper and lower jaws are shown in cut-away views to show internalcam surfaces of the upper jaw 1510 and the reciprocating member 340. Thejaw assembly 1500 may carry engagement surfaces for applyingelectrosurgical energy to tissue as in the previously describedembodiments, as well as cutting means for transecting the engaged tissuevolume. The jaw assembly 1500 relates to the ability of the jawstructure, in one mode of operation, to be used for general grasping anddissecting purposes wherein the distalmost tips 1513 of the jaws canclose tightly on tissue with little movement of the actuator lever 113in the handle of the instrument. At the same time, in another mode ofoperation, the jaw assembly 1500 can close to apply very highcompressive forces on the tissue to enable welding. Thus, the jawstructure may provide (i) a first non-parallel jaw-closed position forgrasping tissue with the distal jaws tips (FIG. 17), and (ii) a secondparallel jaw-closed position for high compression of tissue for theapplication of electrosurgical energy (FIG. 18).

Referring to FIG. 15, the end effector 1500 again has a shaft 104 thatis similar to the shaft 104 as used by the end effector 1200 with first(lower) jaw 1510 comprising a fixed extending portion 1514 of the shaft104. As can be seen in FIG. 15, the second (upper) jaw 1508 is adaptedto close or approximate about longitudinal axis 1515. Theopening-closing mechanism of jaw assembly 1500 provides cam elements andcooperating jaw surfaces for positive engagement between thereciprocating member 340 as described previously (i) for moving the jawsto a closed position to engage tissue, and (ii) for moving the jawstoward the open position thereby providing high opening forces todissect tissue with outer surfaces of the jaw tips 313.

The reciprocating member 340 (FIG. 19) operates as described previouslyto reciprocate within bore 308 of the shaft 104 (FIG. 15). As can beseen in FIG. 15, the distal end 342 of the reciprocating member 340again carries distal flange portions 344A and 344B with a blade-carryingtransverse portion 345 therebetween. The transverse portion 345 slideswithin channels 348 a and 348 b in the paired jaws. In the exampleembodiment of FIG. 15, the first and second jaws 1510 and 1508 againdefine engagement surfaces 1550 a and 1550 b that can deliverelectrosurgical energy to engaged tissue.

In the embodiment of FIG. 15, the upper jaw 1508 has a proximal end 1558that defines a first (proximally-facing) arcuate jaw surface 1560 thatis engaged by a first cam surface element 1562 of reciprocating member340 for opening the jaw. The proximal end 1558 of the upper jaw furtherdefines second (distally-facing) jaw surface portions indicated at 1570a and 1570 a′ that are engaged by second cam element 1572 ofreciprocating member 340 for moving the jaw assembly to an openposition.

The embodiment of FIG. 15 shows that the upper jaw 1508 has a floatingprimary pivot location indicated at P₁ that is provided by theprojecting elements or rectangular pins 1574 (collectively) on eitherside of the channel portions 348 a that slidably extend into bores 1577(collectively) in the lower jaw body (cf. Figure Z3). The lower portionsof the pins 1574 thus allow upper jaw 1508 to rotate while at the sametime the pin-and-bore mechanism allows the upper jaw to move upwardlyaway from the lower jaw.

For example, the degree of “vertical” freedom of movement of the upperjaw allows for the system to “tilt” the distal tip 1513 of upper jaw1508 toward the axis 1515 to thereby allow the distal jaw tips 1513 tograsp tissue. This is termed a non-parallel closed position herein. Thetilting of the jaw is accomplished by providing a plurality of camsurfaces in the upper jaw 1508 and the reciprocating member 340.

As can be seen in FIGS. 15 and 19, the lower and upperlaterally-extending flange portions 344A and 344B of the reciprocatingmember 340 define a transverse dimension d that determines the dimensionof gap g between the engagement surface of the jaws in the fullyjaw-closed position (FIG. 18). The transverse dimension d equals thedimension between inner surfaces of flange portions 344A and 344B thatslidably contact the outer surfaces of both jaws.

FIG. 19 illustrates one embodiment of the reciprocating member 340configured with separate elevated step or cam surfaces 1590 in the lowerflange portions 344A that are adapted to slidably engage the ends 1595of the rectangular pins 1574 on either side of upper jaw 1508. Theelevated cam surfaces 1590 of reciprocating member 340 thus createanother transverse dimension d′ between inner surfaces of the flangeportions 344A and 344B that move the jaws toward either the firstjaw-closed position or the second jaw-closed position.

Now turning to FIGS. 15-18, the sequence of cut-away views illustratehow the multiple cam surfaces cause the jaws to move between a first“tilted” jaw-closed position to a second “high-compression” jaw-closedposition. In FIG. 15, the jaws are in an open position. In FIG. 16, thereciprocating member 340 is moved distally and its cam surface element1562 pushes on jaw surfaces 1560 to move the jaws toward a closedposition wherein the jaws rotate about primary pivot location P₁. InFIG. 16, it can be seen that the elevated cam surfaces 1590 in the lowerflange 344A have not yet engaged the ends 1595 of the rectangular pins1574.

Now turning to FIG. 17, the reciprocating member 340 is moved furtherdistally wherein the elevated cam surfaces 1590 of lower flange 344Ahave now engaged and elevated the ends 1595 of rectangular pins 1574thereby tilting the upper jaw. The upper jaw 1508 is tilted slightly byforces in the direction of the arrows in FIG. 17 as the upper flange1544B holds the upper jaw 1508 at a secondary pivoting locationindicated at P₂—at the same time that the step of the cam surfaceelement 1590 lifts the pins 1574 and the proximal portion 1558 of theupper jaw 1508 upward.

Thus, the system functions by providing a slidable cam mechanism forlifting the proximal end of the jaw while maintaining the medial jawportion in a fixed position to thereby tilt the distal jaw to the secondjaw-closed position, with the pivot occurring generally about secondarypivot P₂ which is distal from the primary pivot location P₁.

FIG. 18 next shows the reciprocating member 340 moved further distallywherein the elevated cam surfaces 1590 of lower flange 344A slidesdistally beyond the ends 1595 of rectangular pins 1574 thus causing theflanges 344A and 344B together with the trailing edge portions 1575 ofthe “I”-beam portion (FIG. 19) of the member 340 to apply very highcompression forces over the entire length of the jaws as indicated bythe arrows in FIG. 18. This position is termed a parallel jaw-closedposition herein. Another advantage is that the jaw structure is in a“locked” position when the reciprocating member 340 is fully advanced.

FIG. 20 illustrates one embodiment of an end effector 2000 comprising afirst jaw member 2002 and a second jaw member 2004 that are configuredto have a parallel closing motion via a linkage system. The end effector2000 may be coupled to the shaft 104, which is shown in FIG. 20 as atransparent outline to illustrate the interior components. The endeffector 2000, in addition to the jaw members 2002, 2004, may comprisepush rods 2012, 2010 and linkage members 2014, 2016 as well as areciprocating member 340′, which may operate similar to thereciprocating member 340 described above. The push rods 2012, 2010 maybe pivotably coupled to the respective jaw members 2002, 2004. The pushrods 2012, 2010 may be pivotably coupled to one another at pivot point2018. Pivot point 2018 may, additionally, be coupled to the shaft 104,for example, to an interior portion of the shaft 104, such that thepivot point 2018 may be substantially restrained from proximal or distalmotion. Pivotable linkage members 2014, 2016 may additionally couple thejaw members 2002, 2004. For example, a linkage member 2014 may bepivotably coupled to the jaw member 2002. Another linkage member 2016may be pivotably coupled to the jaw member 2004. The members 2014, 2016may be pivotably coupled to one another at pivot point 2006. Like pivotpoint 2018, the pivot point 2006 may be coupled to the shaft 104 suchthat it is substantially restrained from proximal or distal motion. Itwill be appreciated that the various pivot points 2006, 2018 as well asother pivotable joints (e.g., between jaw members 2002, 2004 and thevarious push rods 2010, 2012 and linkage members 2014, 2016) may beimplemented by pivot pins or any other suitable pivotable fasteningdevice or method (hinges, etc.). According to various embodiments, thereciprocating member 340′ may define a slot 2008. The pivot point 2018(e.g., the pivotably fastening device implementing the pivot point 2018)may extend through the slot 2008. Accordingly, the reciprocating member340′ may translate distally and proximally without causing any relateddistal or proximal movement of the pivot point 2018.

In FIG. 20, the end effector 2000 is shown in an open position. FIG. 21illustrates the end effector 2000 in a closed position. To transitionthe end effector 2000 from the open position shown in FIG. 20 to theclosed position shown in FIG. 21, the clinician may cause thereciprocating member 340′ to translate distally (e.g., by using theactuator 113 of FIG. 1). As the reciprocating member 340′ translatesdistally, a transverse element 345 of the reciprocating member 340′ maypass through slots in the jaw members 2002, 2004, such as the slot 2022of jaw member 2002 illustrated in FIG. 22. Flanges or shoulder elements344A, 344B of the reciprocating member 340′ may ride outside of all or aportion of the jaw members 2002, 2004, generating a compressive forcetending to close the members 2002, 2004. The compressive force may causethe push rod members 2010, 2012 and the linkage members 2014, 2016 topivot towards one another about the respective pivot points 2018, 2006to the position shown in FIG. 21. The jaw members 2002, 2004 may closein a substantially parallel motion. When the position of the pivotpoints 2018, 2006 is fixed, the jaw members 2002, 2004 may translateslightly distally as they close. This effect is illustrated in FIGS. 20and 21 and indicated in FIG. 20 by arrows 2021. To transition the jawmembers 2002, 2004 from the closed position shown in FIG. 21 to the openposition shown in FIG. 20, the reciprocating member 340′ may beretracted to remove the compressive force. According to variousembodiments, the jaw members 2002, 2004 may then be spring-loaded toreturn to the open position shown in FIG. 20.

FIG. 22 illustrates a top view of one embodiment of the end effector2000. In the view illustrated, optional complimentary push rod members2010′, 2012′, linkage members 2016′, 2014′ and pivot points 2006, 2006′,2018, 2018′ are illustrated on the opposite side of the end effector2000. These push rod members 2010′, 2012′ and linkage members 2014′,2016′ may behave in a manner similar to that of the push rod members2010, 2012 and linkage members 2014, 2016 described above. Asillustrated in FIG. 22, the push rod members 2010, 2012, 2010′, 2012′may be positioned outside of the jaw members 2002, 2004 (e.g., betweenthe jaw members 2002, 2004 and an interior wall 104 a of the shaft 104).Also, as illustrated in FIG. 22, each pair of members may be positionedadjacent one another. For example, push rod members 2010, 2012 areillustrated adjacent to one another, as our push rod members 2010′,2012′ and linkage member pairs 2014, 2016 and 2014′, 2016′. For example,one of the push rod members 2010, 2012 may be positioned outside of theother push rod member 2010, 2012. It will be appreciated that, accordingto various embodiments, complimentary pivot points (e.g., 2006, 2006′and 2018, 2018′) may be implemented by a single pivot pin or otherpivotable fastening device extending through the shaft 104. Regardingcomplimentary pivot points 2018, 2018′, when both are implemented with asingle pivot pin or other pivotable fastening device, such device maypass through the slot 2008 of the reciprocating member 340′ as describedabove.

FIG. 23 illustrates a top view of the end effector 2000 of FIG. 22according to an alternate arrangement 2000′. In FIG. 23, push rodmembers 2012 and 2012′ are illustrated coupled to a proximal end of thevisible jaw member 2002′. Push rod members 2010 and 2010′ may bepositioned below the push rod members 2012, 2012′ from the view shown inFIG. 23. In this way, the jaw member 2002′ may be wider than the jawmember 2002, for a given diameter of the shaft 104.

FIGS. 24 and 25 illustrate one embodiment of an end effector 2000″mounted to the shaft 104 via a clevis 2400. The end effector 2000″ mayfunction in a manner similar to the end effectors 2000 and 2000″described above. Instead of being positioned relative to the shaft 104such that both pivot points 2006, 2018 are within the shaft 104 proper,the end effector 2000″ may comprise a clevis 2400 coupled to the shaft104. The clevis 2400 may extend from the shaft to the pivot point 2006,which may be coupled to the clevis 2400 such that distal and proximalmotion of the pivot point 2006 is substantially arrested. For example,the clevis 2400 may comprise a pair of arms extending from the shaft 104to receive the pivot pin or other pivotable fastening deviceimplementing the pivot point 2006. The clevis 2400 may be shaped suchthat the jaw members 2002, 2004 may fit through, allowing the jawmembers 2002, 2004 to open wider than the diameter of the shaft 104.

FIGS. 26 and 27 illustrate one embodiment of an end effector 2700 havinga single movable jaw member 2702. A second jaw member 2704 may bestationary (e.g., fixed to the shaft 104). A push rod 2708 and linkage2706 may couple the movable jaw member 2702 to either the shaft 104 orthe stationary jaw member 2704. The end effector 2700 may operate in amanner similar to the end effectors 2000, 2000′, and 2000″ describedabove. For example, to transition the end effector 2700 from the openposition shown in FIG. 26 to the closed position shown in FIG. 27, thereciprocating member 340′ may be extended distally. Flange portions344A, 344B of may contact the jaw members 2702, 2704 in a manner similarto that described above, exerting a compressive force on the jaw members2702, 2704. This may cause the movable jaw member 2702 to pivot aboutpivot points 2712, 2714 and in the direction of the arrow 2716 towardsthe stationary jaw member 2704 to the closed position shown in FIG. 27.It will be appreciated that the push rod 2708 and the linkage 2706 maybe positioned in any suitable manner. For example, the push rod 2708 maybe positioned between the jaw members 2702, 2704 and an inner wall ofthe shaft 104, or may be positioned substantially proximal from the jawmembers 2702, 2704.

According to various embodiments, the end effectors 106, 1200, 1500,2000, 2000′, 2000″, 2700 may be used to cut and fasten tissue utilizingelectrical energy. The examples described below are illustrated with theend effector 106. It will be appreciated, however, that similarconfigurations and techniques may be used with any of the end effectorsdescribed above. Referring to the end effector 106 shown in FIGS. 3-4and 7-8, the electrodes 120, 122 of the end effector 106 may be arrangedin any suitable configuration. In use, for example, tissue (not shown)may be captured between the jaw members 108, 110. RF current may flowacross the captured tissue between the opposing polarity electrodes 120,122. This may serve to join the tissue by coagulation, welding, etc. TheRF current may be activated according to any suitable control method.For example, according to various embodiments, the electrodes 120, 122may be used to implement a “power adjustment” approach, a “current-pathdirecting” approach or an approach referred to herein as a “weld” or“fusion” approach. These various approaches are illustrated herein withreference to FIGS. 28-31, which show the walls of an example bloodvessel acted upon by various RF end effectors including those using thepower adjustment and current-path directing approaches from above.

FIG. 28 shows an example embodiment of a vessel having opposing wallportions 2 a and 2 b. FIG. 29 is a graphic illustration of oneembodiment of the opposing vessel walls portions 2 a and 2 b with thetissue divided into a grid with arbitrary micron dimensions. Forexample, the grid may represent 5 microns on each side of the targetedtissue. In order to coagulate or weld tissue, collagen and other proteinmolecules within an engaged tissue volume may be denatured by breakingthe inter- and intra-molecular hydrogen bonds. When heat or other energyis removed (e.g., thermal relaxation), the molecules are re-crosslinkedto create a fused-together tissue mass. It is desirable that eachmicron-dimensioned volume of tissue be elevated to the temperatureneeded to denature the proteins therein in a substantially uniformmanner.

Failing to heat tissue portions in a uniform manner can lead to ohmicheating, which can create portions of tissue that are not effectivelyjoined and reduce the strength of the joint. Non-uniformly denaturedtissue volume may still be “coagulated” and can prevent blood flow insmall vasculature that contains little pressure. However, suchnon-uniformly denatured tissue may not create a seal with significantstrength, for example in 2 mm to 10 mm arteries that contain highpressures. It is often difficult to achieve substantially uniformheating with a bipolar RF device in tissue, whether the tissue is thinor thick. For example, as RF energy density in tissue increases, thetissue surface tends to become desiccated and resistant to additionalohmic heating. Localized tissue desiccation and charring can sometimesoccur almost instantly as tissue impedance rises, which then can resultin a non-uniform seal in the tissue. Also, many RF jaws cause furtherundesirable effects by propagating RF density laterally from the engagedtissue thus causing unwanted collateral thermal damage.

To achieve substantially uniform coagulation, various embodimentsdescribed herein may utilize a “power adjustment” approach, a“current-path directing” approach and/or an approach referred to hereinas a “weld” or “fusion” approach. According to the “power adjustment”approach, the RF generator 124 can rapidly adjust the level of totalpower delivered to the jaws' engagement surfaces in response to feedbackcircuitry, which may be present within the generator 124 and/or at theend effector 106, and may be electrically coupled to the activeelectrodes. The feedback circuitry may measure tissue impedance orelectrode temperature. For example, temperature probes present on thejaw members 109, 110, 1202, 1204 may be in communication with thegenerator 123 and may sense electrode temperature. FIG. 30 illustratesone embodiment of the blood vessel of FIG. 28 acted upon by a deviceimplementing a “power adjustment” approach to energy delivery. Opposingvessel walls 2 a and 2 b are shown compressed with cut-away phantomviews of opposing polarity electrodes 3002, 3004 on either side of thetissue. For example, the electrode 3002 may be positioned on one jawmember 108, 110, while the electrode 3004 may be positioned on theopposite jaw member. One advantage of such an electrode arrangement isthat 100% of each jaw engagement surface comprises an “active” conductorof electrical current—thus no tissue is engaged by an insulator whichtheoretically would cause a dead spot (no ohmic heating) proximate tothe insulator.

FIG. 30 also graphically depicts current paths p in the tissue at anarbitrary time interval that can be microseconds (μs) apart. Suchcurrent paths p would be random and constantly in flux—along transientmost conductive pathways through the tissue between the opposingpolarity electrodes. The thickness of the paths is intended to representthe constantly adjusting power levels. Typically, the duration of energydensity along any current path p is on the order of microseconds and thethermal relaxation time of tissue is on the order of milliseconds.Instruments using the power adjustment approach may be useful forsealing relatively small vessels with relatively low fluid pressure.This is because, given the spatial distribution of the current paths andthe dynamic adjustment of their power levels, it is unlikely that enoughrandom current paths will revisit and maintain each discretemicron-scale tissue volume at the targeted temperature before thermalrelaxation. Also, because the hydration of tissue is constantly reducedduring ohmic heating—any region of more desiccated tissue will lose itsohmic heating, rendering it unable to be “welded” to adjacent tissuevolumes.

In a second “current-path directing” approach, the end effector jawscarry an electrode arrangement in which opposing polarity electrodes arespaced apart by an insulator material, which may cause current to flowwithin an extended path through captured tissue rather than simplybetween surfaces of the first and second jaws. For example, electrodeconfigurations similar to those shown below in FIG. 31 may beimplemented on tissue engaging surfaces 350 a, 350 b, 1236 a, 1236 b.

“Current-path directing” techniques are also used to improve the qualityof energy-delivered seals. FIG. 31 illustrates one embodiment of theblood vessel of FIG. 28 acted upon by a device implementing acurrent-path directing approach to energy delivery. In FIG. 31, vesselwalls 2 a and 2 b are engaged between opposing jaws surfaces withcut-away phantom views of electrodes 3102, 3104, 3106, 3108, withopposing polarity (+) and (−) electrodes (3102, 3104 and 3106, 3108) oneach side of the engaged tissue. For example, electrodes 3102 and 3104may be positioned on one of the jaw members 108, 110, 1202, 1204 whileelectrodes 3106 and 3108 maybe positioned on the opposite jaw member. Aninsulator 3110 is shown in cut-away view that electrically isolates theelectrodes in the jaw. The tissue that directly contacts the insulator3110 will only be ohmically heated when a current path p extends throughthe tissue between the spaced apart electrodes. FIG. 31 graphicallydepicts current paths p at any arbitrary time interval, for example inthe μs range. Again, such current paths p will be random and in constantflux along transient conductive pathways.

A third approach, according to various embodiments, may be referred toas a “weld” or “fusion” approach. The alternative terms of tissue“welding” and tissue “fusion” are used interchangeably herein todescribe thermal treatments of a targeted tissue volume that result in asubstantially uniform fused-together tissue mass, for example in weldingblood vessels that exhibit substantial burst strength immediatelypost-treatment. Such welds may be used in various surgical applicationsincluding, for example, (i) permanently sealing blood vessels in vesseltransection procedures; (ii) welding organ margins in resectionprocedures; (iii) welding other anatomic ducts or lumens where permanentclosure is desired; and also (iv) for performing vessel anastomosis,vessel closure or other procedures that join together anatomicstructures or portions thereof.

The welding or fusion of tissue as disclosed herein may be distinguishedfrom “coagulation”, “hemostasis” and other similar descriptive termsthat generally relate to the collapse and occlusion of blood flow withinsmall blood vessels or vascularized tissue. For example, any surfaceapplication of thermal energy can cause coagulation or hemostasis—butdoes not fall into the category of “welding” as the term is used herein.Such surface coagulation does not create a weld that provides anysubstantial strength in the treated tissue.

A “weld,” for example, may result from the thermally-induceddenaturation of collagen and other protein molecules in a targetedtissue volume to create a transient liquid or gel-like proteinaceousamalgam. A selected energy density may be provided in the targetedtissue to cause hydrothermal breakdown of intra- and intermolecularhydrogen crosslinks in collagen and other proteins. The denaturedamalgam is maintained at a selected level of hydration—withoutdesiccation—for a selected time interval, which may be very brief. Thetargeted tissue volume may be maintained under a selected very highlevel of mechanical compression to insure that the unwound strands ofthe denatured proteins are in close proximity to allow theirintertwining and entanglement. Upon thermal relaxation, the intermixedamalgam results in protein entanglement as re-crosslinking orrenaturation occurs to thereby cause a uniform fused-together mass.

To implement the welding described above, the electrodes 120, 122 (orelectrodes that are part of the other end effector embodiments describedherein) may, one or both, comprise an electrically conductive portion,such as copper or another suitable metal or alloy, and a portioncomprising a positive temperature coefficient (PTC) material having aselected increased resistance that differs at selected increasedtemperatures thereof. The PTC material may be positioned between theelectrically conductive portion and any tissue to be acted upon by theend effector 106. One type of PTC material is a ceramic that can beengineered to exhibit a selected positively slope curve oftemperature-resistance over a temperature range of about 37° C. to 100°C. Another type of PCT material may comprise a polymer having similarproperties. The region at the higher end of such a temperature rangebrackets a targeted “thermal treatment range” at which tissue can beeffectively welded. The selected resistance of the PTC matrix at theupper end of the temperature range may substantially terminate currentflow therethrough.

In operation, it can be understood that the electrodes 120 or 122 willapply active RF energy (ohmic heating within) to the engaged tissueuntil the point in time that the PTC matrix is heated to exceed themaximum of the thermal treatment range. Thereafter, RF current flow fromthe engagement surface will be lessened—depending on the relativesurface areas of the first and second electrodes 120, 122. This instantand automatic reduction of RF energy application may prevent anysubstantial dehydration of tissue proximate to the engagement plane. Bythus maintaining an optimal level of moisture around the engagementplane, the working end can more effectively apply energy to thetissue—and provide a weld thicker tissues with limited collateralthermal effects.

In various embodiments, surgical instruments utilizing variousembodiments of the transection and sealing instrument 100, with thevarious end effectors and actuating mechanisms described herein may beemployed in conjunction with a flexible endoscope. FIG. 32 illustratesone embodiment of an endoscope 3214 (illustrated here as a gastroscope)inserted into the upper gastrointestinal tract of a patient. Theendoscope 3214 may be any suitable endoscope including, for example, theGIF-100 model available from Olympus Corporation. The endoscope 3214 hasa distal end 3216 that may include various optical channels,illumination channels, and working channels. According to variousembodiments, the endoscope 3214 may be a flexible endoscope.

FIG. 33 illustrates one embodiment of a distal portion 3216 of theendoscope 3214, which may be used with the transection and sealinginstrument 100 described herein. The example endoscope 3214 showncomprises a distal face 3204, which defines the distal ends ofillumination channels 3208, an optical channel 3206 and a workingchannel 3210. The illumination channels 3208 may comprise one or moreoptical fibers or other suitable waveguides for directing light from aproximally positioned light source (not shown) to the surgical site. Theoptical channel 3206 may comprise one or more optical fibers or othersuitable waveguides for receiving and transmitting an image of thesurgical site proximally to a position where the image may be viewed bythe clinician operating the endoscope 3214. As described above, theworking channel 3210 may allow the clinician to introduce one or moresurgical tools to the surgical site. Examples of such surgical toolsinclude scissors, cautery knives, suturing devices, and dissectors. Itwill be appreciated that the endoscope 3214 is but one example of anendoscope that may be used in accordance with various embodiments.Endoscopes having alternate configurations of optical channels 3206,illumination channels 3208 and/or working channels 3210 may also beused. According to various embodiments, the endoscope 3214 may be, ormay be used in conjunction with, steerable devices such as traditionalflexible endoscopes or steerable overtubes as described in U.S. PatentApplication Publication No. 2010/0010299, incorporated herein byreference. Combinations of flexible endoscopes and steerable overtubesmay also be used in some embodiments.

In at least one such embodiment, the endoscope 3214, a laparoscope, or athoracoscope, for example, may be introduced into the patienttrans-anally through the colon, the abdomen via an incision or keyholeand a trocar, or trans-orally through the esophagus or trans-vaginallythrough the cervix, for example. These devices may assist the clinicianto guide and position the transection and sealing instrument 100 nearthe tissue treatment region to treat diseased tissue on organs such asthe liver, for example.

In one embodiment, Natural Orifice Translumenal Endoscopic Surgery(NOTES)™ techniques may be employed to introduce the endoscope 3214 andvarious instruments into the patient and carry out the variousprocedures described herein. A NOTES™ technique is a minimally invasivetherapeutic procedure that may be employed to treat diseased tissue orperform other therapeutic operations through a natural opening of thepatient without making incisions in the abdomen. A natural opening maybe the mouth, anus, and/or vagina. Medical implantable instruments maybe introduced into the patient to the target area via the naturalopening. In a NOTES™ technique, a clinician inserts a flexible endoscopeinto one or more natural openings of the patient to view the targetarea, for example, using a camera. During endoscopic surgery, theclinician inserts surgical devices through one or more lumens or workingchannels of the endoscope 3214 to perform various key surgicalactivities (KSA). These KSAs include forming an anastomosis betweenorgans, performing dissections, repairing ulcers and other wounds.Although the devices and methods described herein may be used withNOTES™ techniques, it will be appreciated that they may also be usedwith other surgical techniques including, for example, other endoscopictechniques, and laparoscopic techniques.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician manipulating an end of aninstrument extending from the clinician to a surgical site (e.g.,through a trocar, through a natural orifice or through an open surgicalsite). The term “proximal” refers to the portion closest to theclinician, and the term “distal” refers to the portion located away fromthe clinician. It will be further appreciated that for conciseness andclarity, spatial terms such as “vertical,” “horizontal,” “up,” and“down” may be used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

While several embodiments have been illustrated and described, and whileseveral illustrative embodiments have been described in considerabledetail, the described embodiments are not intended to restrict or in anyway limit the scope of the appended claims to such detail. Additionaladvantages and modifications may readily appear to those skilled in theart. Those of ordinary skill in the art will readily appreciate thedifferent advantages provided by these various embodiments.

While several embodiments have been described, it should be apparent,however, that various modifications, alterations and adaptations tothose embodiments may occur to persons skilled in the art with theattainment of some or all of the advantages of the embodiments. Forexample, according to various embodiments, a single component may bereplaced by multiple components, and multiple components may be replacedby a single component, to perform a given function or functions. Thedescribed embodiments are therefore intended to cover all suchmodifications, alterations and adaptations without departing from thescope of the appended claims.

Various embodiments are directed to apparatuses, systems, and methodsfor the treatment of tissue. Numerous specific details are set forth toprovide a thorough understanding of the overall structure, function,manufacture, and use of the embodiments as described in thespecification and illustrated in the accompanying drawings. It will beunderstood by those skilled in the art, however, that the embodimentsmay be practiced without such specific details. In other instances,well-known operations, components, and elements have not been describedin detail so as not to obscure the embodiments described in thespecification. Those of ordinary skill in the art will understand thatthe embodiments described and illustrated herein are non-limitingexamples, and thus it can be appreciated that the specific structuraland functional details disclosed herein may be representative andillustrative. Variations and changes thereto may be made withoutdeparting from the scope of the claims.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment”, or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment.Thus, appearances of the phrases “in various embodiments,” “in someembodiments,” “in one embodiment,” or “in an embodiment”, or the like,in places throughout the specification are not necessarily all referringto the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. Thus, the particular features, structures, orcharacteristics illustrated or described in connection with oneembodiment may be combined, in whole or in part, with the featuresstructures, or characteristics of one or more other embodiments withoutlimitation.

The entire disclosures of the following non-provisional United Statespatents are hereby incorporated by reference herein:

U.S. Pat. No. 7,381,209, entitled ELECTROSURGICAL INSTRUMENT;

U.S. Pat. No. 7,354,440, entitled ELECTROSURGICAL INSTRUMENT AND METHODOF USE;

U.S. Pat. No. 7,311,709, entitled ELECTROSURGICAL INSTRUMENT AND METHODOF USE;

U.S. Pat. No. 7,309,849, entitled POLYMER COMPOSITIONS EXHIBITING A PTCPROPERTY AND METHODS OF FABRICATION;

U.S. Pat. No. 7,220,951, entitled SURGICAL SEALING SURFACES AND METHODSOF USE;

U.S. Pat. No. 7,189,233, entitled ELECTROSURGICAL INSTRUMENT;

U.S. Pat. No. 7,186,253, entitled ELECTROSURGICAL JAW STRUCTURE FORCONTROLLED ENERGY DELIVERY;

U.S. Pat. No. 7,169,146, entitled ELECTROSURGICAL PROBE AND METHOD OFUSE;

U.S. Pat. No. 7,125,409, entitled ELECTROSURGICAL WORKING END FORCONTROLLED ENERGY DELIVERY;

U.S. Pat. No. 7,112,201, entitled ELECTROSURGICAL INSTRUMENT AND METHODOF USE;

U.S. Patent Application Publication No. 2010/0010299, entitledENDOSCOPIC TRANSLUMENAL ARTICULATABLE STEERABLE OVERTUBE; and

U.S. Patent Application Publication No. 2006/0111735, entitled CLOSINGASSEMBLIES FOR CLAMPING DEVICE.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialdoes not conflict with existing definitions, statements or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

The devices disclosed herein may be designed to be disposed of after asingle use, or they may be designed to be used multiple times. In eithercase, however, the device may be reconditioned for reuse after at leastone use. Reconditioning may include a combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicemay be disassembled, and any number of particular pieces or parts of thedevice may be selectively replaced or removed in any combination. Uponcleaning and/or replacement of particular parts, the device may bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Those ofordinary skill in the art will appreciate that the reconditioning of adevice may utilize a variety of different techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of thisapplication.

Preferably, the embodiments described herein will be processed beforesurgery. First a new or used instrument is obtained and, if necessary,cleaned. The instrument may then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK® bag. The container and instrument are thenplaced in a field of radiation that may penetrate the container, such asgamma radiation, x-rays, or higher energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument may then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

The embodiments are not to be construed as limited to the particularembodiments disclosed. The embodiments are therefore to be regarded asillustrative rather than restrictive. Variations and changes may be madeby others without departing from the scope of the claims. Accordingly,it is expressly intended that all such equivalents, variations andchanges that fall within the scope of the claims be embraced thereby.

In summary, numerous benefits have been described which result fromemploying the embodiments described herein. The foregoing description ofthe one or more embodiments has been presented for purposes ofillustration and description. It is not intended to be exhaustive orlimiting to the precise form disclosed. Modifications or variations arepossible in light of the above teachings. The one or more embodimentswere chosen and described in order to illustrate principles andpractical applications to thereby enable one of ordinary skill in theart to utilize the various embodiments and with various modifications asare suited to the particular use contemplated. It is intended that theclaims submitted herewith define the overall scope.

What is claimed is:
 1. A surgical instrument comprising: a handle; ashaft coupled to the handle and extending distally along a longitudinalaxis; an end effector positioned at a distal end of the shaft, whereinthe end effector comprises: a first jaw member defining a firstlongitudinal slot; a second jaw member defining a second longitudinalslot; a first push rod member having a distally directed end pivotablycoupled to the first jaw member and a proximally directed end pivotablycoupled to at least one of the shaft and the second jaw member at afirst pivot point; a first linkage member having a distally directed endpivotably coupled to the first jaw member and a proximally directed endpivotably coupled to at least one of the shaft and the second jaw memberat a second pivot point; and a reciprocating member translatabledistally and proximally parallel to the longitudinal axis through thefirst longitudinal slot and the second longitudinal slot, wherein adistal portion of the reciprocating member defines a blade, wherein thereciprocating member defines a transverse element positioned to passthrough the first longitudinal slot and a first shoulder element coupledto the transverse element and substantially perpendicular to thetransverse element, wherein upon distal motion of the reciprocatingmember, the first shoulder element contacts the first push rod member,exerting a force on at least the first jaw member causing the first jawmember to translate towards the second jaw member in a substantiallyparallel motion.
 2. The surgical instrument of claim 1, wherein thesecond jaw member is coupled to the shaft.
 3. The surgical instrument ofclaim 2, further comprising: a second push rod member having a distallydirected end pivotably coupled to the first jaw member and a proximallydirected end pivotably coupled to at least one of the shaft and thesecond jaw member at a third pivot point opposite the first pivot point.4. The surgical instrument of claim 3, wherein the first and the thirdpivot points are implemented by a single pivotable fastening device. 5.The surgical instrument of claim 4, wherein the pivotable fasteningdevice is a pivot pin.
 6. The surgical instrument of claim 2, furthercomprising: a second linkage member having a distally directed endpivotably coupled to the first jaw member and a proximally directed endpivotably coupled to at least one of the shaft and the second jaw memberat the second pivot point.
 7. The surgical instrument of claim 2,wherein the first push rod member is positioned between the first jawmember and an interior wall of the shaft.
 8. The surgical instrument ofclaim 2, wherein the first push rod member is positioned substantiallyproximal from the first and second jaw members.
 9. The surgicalinstrument of claim 2, wherein the reciprocating member defines alongitudinal slot and wherein the slot receives at least a portion ofthe first pivot point.
 10. The surgical instrument of claim 1, furthercomprising: a second push rod member having a distally directed endpivotably coupled to the second jaw member and a proximally directed endpivotably coupled to the shaft at the first pivot point; and a secondlinkage member having a distally directed end pivotably coupled to thesecond jaw member and a proximally directed end pivotably coupled to thesecond pivot point, wherein the distal motion of the reciprocatingmember exerts the force on the first and second jaw members also causingthe second jaw member to translate towards the first jaw member in asubstantially parallel motion.
 11. The surgical instrument of claim 10,wherein the second pivot point is coupled to a clevis, and wherein theclevis is coupled to the shaft.
 12. The surgical instrument of claim 10,further comprising: a third push rod member having a distally directedend pivotably coupled to the first jaw member and a proximally directedend pivotably coupled to the shaft at a third pivot point opposite thefirst pivot point; a fourth push rod member having a distally directedend pivotably coupled to the second jaw member and a proximally directedend pivotably coupled to the shaft at the third pivot point.
 13. Thesurgical instrument of claim 12, wherein the first and the third pivotpoints are implemented by a single pivotable fastening device.
 14. Thesurgical instrument of claim 13, wherein the pivotable fastening deviceis a pivot pin.
 15. The surgical instrument of claim 10, furthercomprising: a third linkage member having a distally directed endpivotably coupled to the first jaw member and a proximally directed endpivotably coupled to a fourth pivot point opposite the second pivotpoint; a fourth linkage member having a distally directed end pivotablycoupled to the second jaw member and a proximally directed end pivotablycoupled to the fourth pivot point.
 16. The surgical instrument of claim10, wherein the first and the second push rod members are positionedbetween the first jaw member and an interior wall of the shaft.
 17. Thesurgical instrument of claim 10, wherein the first push rod member ispositioned between the second push rod member and an interior wall ofthe shaft.
 18. The surgical instrument of claim 10, wherein the firstand second push rod members are positioned substantially proximal fromthe first and second jaw members.
 19. The surgical instrument of claim10, wherein the reciprocating member defines a longitudinal slot andwherein the slot receives at least a portion of a pivotable fasteningdevice implementing the first pivot point.